Turning Assistant for a Vehicle

ABSTRACT

A method controls a first vehicle in respect of an oncoming second vehicle. The method determines a turning situation of the first vehicle, in which an expected first trajectory of the first vehicle crosses an expected second trajectory of the second vehicle, and controls the first vehicle in such a way that, during the turning situation, a predetermined distance between the vehicles is maintained. The control includes an influencing of the direction of travel of the first vehicle.

BACKGROUND AND SUMMARY

The invention relates to the control of a vehicle. In particular, theinvention relates to the control of a vehicle during turning in theevent of oncoming traffic.

A vehicle which is located on a road having oncoming traffic can cross alane provided for oncoming vehicles when turning. In right-hand traffic,in particular turning left, and in left-hand traffic, turning right cancomprise crossing the oncoming lane. The vehicle is to cross oncomingtraffic in such a way that oncoming traffic is not endangered orobstructed.

If the oncoming traffic comprises a sequence of multiple vehicles, itcan thus be necessary to cross between these vehicles. The determinationof a point in time for the crossing can be difficult, and an incorrectdetermination, for example, due to an incorrectly estimated travel speedof the oncoming traffic, can significantly increase a risk of collision.

One underlying object of the invention is to provide an improvedtechnology for improving the safety of a vehicle, which crosses oncomingtraffic in a turning situation. The invention achieves the object bymeans of the subjects of the independent claims. Dependent claimsreflect preferred embodiments.

According to a first aspect of the present invention, a method forcontrolling a first vehicle with respect to an oncoming second vehicleis described. According to the method, a turning situation of the firstvehicle is determined, in which an expected first trajectory of thefirst vehicle crosses an expected second trajectory of the secondvehicle. The first vehicle is then controlled in such a way that apredetermined distance is maintained between the vehicles during theturning situation. The control comprises influencing the traveldirection of the first vehicle in this case.

The turning situation can exist when the first vehicle is located on aroad having at least two lanes, the assigned travel directions of whichare opposite to one another, or if vehicles having opposing traveldirections share a lane. In right-hand traffic, the turning situationcan comprise turning of the first vehicle to the left (turning left), inleft-hand traffic, it can comprise turning to the right (turning right).Solely by way of example, reference is primarily made herein toright-hand traffic; a corresponding procedure can take place accordinglyin the case of left-hand traffic.

The second vehicle typically follows the course of the road and does notturn itself. However, the technology presented herein can also beapplied if the second vehicle turns. For the presented technology, theroad can also comprise more than two lanes. A permitted travel orturning direction can be predefined individually for each of theexisting lanes, in particular the turning vehicle can be located on aturn lane. In addition, more than two second vehicles can also bepresent, wherein the second vehicles can be underway in succession onthe same lane or on lanes adjacent to one another. In this case, thevehicle has to cross behind one of the second vehicles and in front ofanother of the second vehicles.

By adapting the travel direction of the first vehicle during theturning, the planned first trajectory during the turning can be madeflatter or steeper than initially planned, so that the lane assigned tothe second vehicle can be entered and left somewhat earlier or somewhatlater at predetermined travel speed of the first vehicle. A distance ofthe first vehicle to the second vehicle can thus be controlled byinfluencing the travel direction of the first vehicle.

The distance between the vehicles can be determined with respect to thetravel direction and/or travel speed of one of the vehicles. A largerregion can thus be kept free in front of the second vehicle than behindor laterally to the second vehicle. This can apply accordingly to thefirst vehicle. The distance to be maintained to a vehicle can beselected in dependence on its travel speed, so that, for example, anenlarged distance is kept free in front of a vehicle if the vehicledrives faster. A distance to be maintained behind or laterally to thevehicle can be influenced less or not at all by the traveled velocity.

It is particularly preferred that a steering intervention is controlledon the first vehicle. The steering intervention can act in particular ona steering device for influencing a travel direction. The first vehicletypically comprises two axles each having at least one wheel, and wheelsof the front axle can be steered in that they are rotated around avertical axis. In other embodiments, one wheel of another axle can alsobe steerable.

The technology presented herein can be applied to a two-wheeled vehicleor a vehicle having more than two wheels. The vehicle preferablycomprises two axles each having two wheels, which run in two tracks.Furthermore, the vehicle preferably comprises a motor vehicle, inparticular a passenger vehicle, a truck, or a bus.

The steering intervention can comprise a predetermined steering force,wherein the steering force can be counteracted by a driver of the firstvehicle. The predetermined steering force is preferably sufficientlylarge to control a travel direction of the first vehicle and, on theother hand, sufficiently small to be compensated or overridden by adriver of the first vehicle. In one embodiment, the steering force iseffectuated by means of a control motor of the steering system, forexample, by a hydraulic or electrical drive, which can be part of asteering aid or power steering system. In one embodiment, the presentedtechnology can also manage without a driver of the first vehicle; inthis case, the steering force used does not have to be restricted to anamount that can be overridden by a person.

In a further preferred embodiment, a travel speed of the first vehicleis additionally reduced before the crossing. The reduction of the travelspeed can be used in particular to delay a point in time at which thefirst vehicle plunges into the lane of the second vehicle. The firstvehicle can first pass the trajectory of the second vehicle, forexample, when the second vehicle has already driven past. In combinationwith a steeper turning trajectory, by reducing the travel speed, thepredetermined distance of the first vehicle to the second can bemaintained in an improved manner. Optionally, the deceleration takesplace to a standstill. The deceleration of the travel speed ispreferably ended before the vehicle penetrates into a driving region ofthe other vehicle. In another variant, the travel speed of the firstvehicle can also be increased. In combination with a flatter turningtrajectory, the first vehicle can thus turn better in front of thesecond one, without infringing the predetermined distance to it.

The travel direction of the first vehicle can be dynamically controlledas a function of a travel speed of the first vehicle. A travel speed ofthe second vehicle can be taken into consideration dynamically in acorresponding manner. By way of the dynamic adaptation, the method canbe used in an improved manner to assist a human driver, who controls thevelocity of the first vehicle. For example, if a flatter turningtrajectory is controlled to cross the lane of the second vehicle in atimely manner before its approach, the influencing of the trajectory canthus be reduced if it is established that the driver accelerates thefirst vehicle more strongly than assumed. In a corresponding manner, theinfluencing can be strengthened if it is established that the firstvehicle is driven more slowly than assumed. A corresponding adaptationof the influencing of the travel direction of the first vehicle can takeplace when crossing behind the second vehicle. In one embodiment, atravel direction change of the second vehicle is also taken intoconsideration, for example, if the second vehicle changes the lane.

In general, it is to be noted that in the case of multiple secondvehicles, between which the first vehicle travels through when turning,the crossing behind a preceding second vehicle and the crossing in frontof a following second vehicle can be controlled simultaneously.

The travel direction of the first vehicle can be controlled morestrongly in the direction of the turning to enlarge a distance to theapproaching second vehicle, or to maintain in an improved manner apredetermined distance to the front end of the second vehicle. Thisvariant is typically applied in the case of crossing of the firstvehicle in front of the second vehicle. When turning left (in right-handtraffic), initially stronger steering to the left can thus take place,when turning right (in left-hand traffic) initially stronger steering tothe right can take place. This influencing of the travel direction ofthe first vehicle is also described herein as controlling a flattertrajectory.

Vice versa, the travel direction of the first vehicle can also becontrolled less in the direction of the turning to enlarge a distance tothe second vehicle moving away. This variant is typically applied duringcrossing of the first vehicle behind the second vehicle. Thisinfluencing of the travel direction of the first vehicle is alsodescribed herein as controlling a steeper trajectory.

The influencing of the travel direction can also take into considerationa further road user, who can be located in the region of the turningsituation. The further road user can comprise, for example, apedestrian, a bicyclist, or a third vehicle who crosses the trajectoryof the first vehicle. For example, the first vehicle can be controlledin such a way that a predetermined distance is maintained to a furtherroad user. It can also be determined whether in the region of theturning situation—typically in the region of an intersection of tworoads—sufficient space is available for traveling the changed firsttrajectory. Existing free space is as much as possible not to betraversed by a planned trajectory of the further road user. In oneembodiment, the first vehicle can be stopped if necessary after crossingthe second trajectory in order to let the other road user pass in frontof it.

After the complete crossing of the second trajectory, the first vehiclecan be returned to the original first trajectory. The first vehicle ispreferably controlled in such a way that its trajectory only deviates inthe region of the turning situation from the initially plannedtrajectory. In particular, it is preferred that the first vehicle afterthe turning occupies in a timely manner a lane of the road assigned toit, into which it has turned.

In still a further embodiment, an acceleration intention of a driver ofthe first vehicle is recognized and the influencing of the traveldirection of the first vehicle is switched off. In particular, it can berecognized that the driver desires a maximum acceleration. In this way,a driver of the first vehicle can quickly, directly, and completely takeover the control of the travel direction of the first vehicle.Influencing described herein of the travel speed can also be switchedoff in this case.

According to a second aspect of the present invention, a device forcontrolling a first vehicle with respect to an oncoming second vehiclecomprises a first unit for determining an expected first trajectory ofthe first vehicle; a second unit for determining an expected secondtrajectory of the second vehicle; a processing unit; and an interfacefor connection to a unit for influencing a travel direction of the firstvehicle. The processing unit is configured to determine a turningsituation in which the determined first trajectory crosses thedetermined second trajectory; and to control the travel direction of thefirst vehicle by means of influencing the travel direction in such a waythat during the turning situation, a predetermined distance ismaintained between the vehicles.

The processing unit can be configured to entirely or partially execute amethod described herein. For this purpose, the processing unit cancomprise a programmable microcomputer or microcontroller and the methodcan be provided in the form of a computer program product having programcode means. The computer program product can also be stored on acomputer-readable data carrier. Features or advantages of the method canbe transferred to the device or vice versa.

The device can furthermore comprise an interface for connection to aunit for influencing a travel speed of the first vehicle, wherein theprocessing unit is configured to decrease and/or increase a travel speedof the first vehicle before the crossing. This unit can in particularcomprise a braking system. The travel speed can be influenced togetherwith the travel direction of the first vehicle in such a way that apredetermined distance is maintained between the first and the secondvehicle. Different influences of the travel direction can take placehere, depending on whether the first vehicle crosses the secondtrajectory before or after the second vehicle has passed the firstvehicle.

According to a third aspect of the present invention, a vehiclecomprises a device described herein. The vehicle preferably comprises amotor vehicle, in particular a passenger vehicle.

The invention will now be described in more detail with reference to theappended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary turning situation;

FIG. 2 illustrates an exemplary device for controlling a vehicle; and

FIG. 3 illustrates a flow chart of a method for controlling a vehicle.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exemplary turning situation. A first lane 105 and asecond lane 110 are provided on a road 100, the provided traveldirections of which are opposite to one another. The illustration ofFIG. 1 is based on right-hand traffic by way of example; the proceduredescribed hereinafter takes place accordingly in the case of left-handtraffic with exchanged directions. On the first lane 105, a firstvehicle 115 is located, toward which a second vehicle 120 is coming onthe second lane 110. It is planned for the first vehicle 115 to turn tothe left into a further road 125, and in this case to travel through thesecond lane 110 in the transverse direction. A control device 130 forcontrolling a travel direction of the first vehicle 115 is located onboard the first vehicle 115. In the present illustration, the road 105extends straight and the second vehicle 120 follows this road 105. Inanother embodiment, the road 105 can also extend in a curve. The secondvehicle 120 can also turn, so that under certain circumstances it leavesthe road 105. In the case of a curving preference road, the secondvehicle 120 can travel through a curve and nonetheless remain on theoriginal road 105. Practically, still other combinations are alsoconceivable. If the first vehicle 115 should have the right-of-way overthe second vehicle 120, the technology described herein can thus notnecessarily be required; however, it can nonetheless be applied forsafety reasons.

In the illustrated situation, the first vehicle 115 follows a firstexpected trajectory 135, and the second vehicle 120 follows a secondexpected trajectory 140. The first vehicle 115 is required to yield tothe second vehicle 120; its turning maneuver is to be controlled as muchas possible so that a predetermined distance is maintained between thevehicles 115, 120. The distance is preferably dimensioned in such a waythat there is no reason to change the second trajectory 140 of thesecond vehicle 120.

The turning situation comprises crossing of the expected trajectories135 and 140. A turning process is understood hereinafter as a maneuverof the first vehicle 115 in which it moves from its lane 105 on the road100 onto the further road 125, wherein it crosses the second lane 110.More precisely, the turning process can begin as soon as the firstvehicle 115 penetrates with its outer outline into the second lane 110,and can end as soon as its outer outline has completely left the secondlane 110 after the traversal. Instead of the second lane 110, athree-dimensional object can also be observed, which comprises the setof all points at which the second vehicle 120 can be located in thecontext of the turning process. This object is similar to a tube alongthe road 100 and is sometimes referred to as a “driving tube”.Optionally, for these observations, the outer outline of one of thevehicles 115, 120 can be enlarged in a predetermined manner before theformation of the driving tube in order to form a safety margin.

A distance between the vehicles 115, 120 at a predetermined point intime can be determined as the smallest geometrical distance betweenouter outlines of the vehicles 115, 120. It is presumed here that theoutlines do not penetrate; the distance is thus preferably positivelydefined. For the first vehicle 115, a first safety distance 145 can bedefined, and/or for the second vehicle 120, a second safety distance 150can be defined.

A safety distance 145, 150 comprises in any case an outer outline of theassigned vehicle 115, 120 and can be enlarged in relation thereto in apredetermined manner. In particular, the enlarging can be constant inthe lateral direction of the vehicle 115, 120, wherein the enlargedlateral outline is preferably not wider than the respective lane 110,115. An enlargement in the travel direction can be dependent on a travelspeed of the respective vehicle 115, 120, wherein a high travel speedcan cause a strong enlargement and a low travel speed can cause a lowenlargement or none at all. An enlargement of the outline against thetravel direction can be constant or also dependent on the travel speed,wherein it is preferred that the enlargement against the traveldirection is always less than that in the travel direction. In oneembodiment, the safety distance 145, 150 extends along an assignedexpected trajectory 135, 140.

A predetermined distance between the vehicles 115, 120 can be maintainedif the safety distances 145, 150 neither touch nor penetrate oneanother.

The first vehicle 115 can cross the second lane 110 in general before orbehind the second vehicle 120. If the safety distances 145, 150 threatento touch one another when the first vehicle 115 follows the expectedfirst trajectory 135, the first vehicle can thus be controlled on aflatter first trajectory 135.1 or on a steeper trajectory 135.2. Theflatter trajectory 135.1 can in particular enlarge a distance of thefirst vehicle 115 in front of the second vehicle 120, while the steepertrajectory 135.2 can in particular enlarge a distance of the firstvehicle 115 behind the second vehicle 120.

When controlling the travel direction of the first vehicle 110 on one ofthe changed trajectories 135.1 or 135.2, it can be ensured that nofurther road user 155 is obstructed. In the present case, the furtherroad user 155 comprises, for example, a pedestrian, who crosses thefurther road 125. In a similar manner as described above with respect tothe vehicles 115, 120, a predetermined distance can be maintainedbetween the first vehicle 115 and the further road user 155. An assignedsafety distance (not shown) and/or an expected trajectory 160 of thefurther road user 155 can be taken into consideration here.

It is to be noted that the control of the trajectory 135 of the firstvehicle 115 can take place additionally or alternatively to a control ofthe travel speed of the first vehicle 115. The first vehicle 115 can bebraked to a standstill if necessary; this preferably takes place outsidethe above-described driving tube of the second vehicle 120. Thetrajectory 135 can be controlled starting from a stationary or atraveling first vehicle 115.

FIG. 2 shows an exemplary device 130 for controlling a first vehicle115. The device 130 is preferably configured to be attached on board thefirst vehicle 115. It comprises a processing unit 205, and a firstdevice 210 for determining the first expected trajectory 135 and asecond device 215 for determining the second expected trajectory 140.The first device 210 can comprise one or more sensors which determine,for example, a movement direction, an acceleration, and/or a plannedroute. The movement direction can be determined, for example, by meansof a compass, a navigation system, or an inertial system, theacceleration by means of an acceleration sensor, on the basis of asteering angle, or due to an actuation of an acceleration or brakingsystem of the first vehicle 115. The planned route can be provided by aroute planning system.

The second device 215 can comprise a sensor 220 for scanning thesurroundings of the first vehicle 115, in particular for scanning thesecond vehicle 120. The sensor 220 can comprise, for example, one ormore optical sensors, a radar sensor, and/or a LiDAR sensor. Items ofmovement information about the second vehicle 120 can also be receivedby means of a communication interface 225, for example, from the secondvehicle 120 or from a central instance. In particular C2X technologiescan be used for this purpose, for example, C2C communication(car-to-car; vehicle-to-vehicle) or C2I (car-to-infrastructure;vehicle-to-infrastructure).

The processing unit can also determine whether a turning situationexists at all on the basis of a geographic position of the first vehicle115 and items of map information, which comprise a course of the roads100 and 125. The geographic position of the first vehicle 115 can bedetermined by means of a position sensor 230, for example, a receiver ofa navigation system, which is satellite-based in particular, and theitems of map information can be stored in a map memory 235.

The processing unit 205 can be connected by means of a first interface240 to a steering unit 245 and/or by means of a second interface 250 toa drive or braking unit 255 of the first vehicle 115, in order toinfluence a travel direction or a travel speed of the first vehicle 115.

FIG. 3 shows a flow chart of an exemplary method 300 for controlling afirst vehicle 115. In a first step 305, an expected first trajectory 135of the first vehicle 115 can be determined and in a step 310, anexpected second trajectory 140 of the second vehicle 120 can bedetermined. In a step 315, an existing turning situation can bedetermined. For this purpose, it can be determined whether the vehicles115, 120 are located in a region which permits a turning maneuver of thefirst vehicle 115 with crossing of the trajectory 140 of the secondvehicle 120. Such a region can in particular comprise an intersection oftwo roads 100, 125. A direction intention of the first vehicle 115 canbe determined on the basis of further locally available items ofinformation.

If a turning situation exists, it can thus be determined in a step 320whether on the basis of the determined expected trajectories 135, 140, apredetermined distance between the vehicles 115, 120 is expected to beundershot. If this is the case, it can thus be distinguished whether thefirst vehicle 115 crosses the trajectory 140 or lane 110 of the secondvehicle in front of or behind the second vehicle 120. Both cases aredescribed hereinafter; a combination of both cases when crossing througha column of second vehicles 120 can result accordingly.

In a step 325, it can be determined that the first vehicle 115 passes infront of the second vehicle 120. In a step 330, it can be determinedwhether sufficient free space is present in the region of the plannedturning maneuver to modify the first expected trajectory 135. Ifsufficient free space is present, in a step 335, a flatter firsttrajectory 135.1 can be determined. Optionally, in a step 340, anincrease of the travel speed of the first vehicle 115 can be determined.

In a step 345, the flatter trajectory 135.1 and/or the determinedincreased travel speed can be controlled. If it should be determinedthat neither a change of the travel direction nor the travel speed nor acombination of both measures can prevent an infringement of thepredetermined distance between the vehicles 115, 120, a signal can thusbe output. The signal can be directed to one of the drivers of thevehicles 115, 120. On the basis of the signal, a unit for minimizingaccident damage on one of the vehicles 115, 120 can be activated, forexample, a belt tensioner or a pre-crash system.

In a further embodiment, the turning maneuver can also be terminatedupon the signal. For this purpose, the first vehicle 115 can betransferred into a safe state, which can in particular comprise astandstill and which preferably is assumed at a point in the region ofthe turning process at which the first vehicle 115 as much as possibleis not in the way of any other road user 120, 155.

The safe state can also comprise that the first vehicle 115 iscontrolled further along the road 100. At the same time, the firstvehicle 115 can be decelerated, preferably to a standstill. In this way,a collision with the second vehicle 120 can be prevented in an improvedmanner. In this embodiment, a driver can also override an initiatedsteering force and/or an initiated acceleration or deceleration.

Following step 320, it can also be determined in a step 350 that thefirst vehicle 115 passes behind the second vehicle 120. For thispurpose, the first vehicle 115 has to wait until the oncoming secondvehicle 120 has traveled past it, before it turns into the second lane110. Steps 355-365 then following can correspond in pairs toabove-described steps 330-340. In a step 355, it can be determinedwhether sufficient free space for influencing the first trajectory 135exists in the region of the planned turning process. In a step 350, asteeper trajectory 135.2 can be determined if sufficient free space wasdetermined. In a step 365, a reduced travel speed of the first vehicle115 can be determined. The reduction typically ends before the actualturning maneuver and can comprise braking of the first vehicle 115 to astandstill. In step 345, the determined trajectory 135.2 and/or thereduced travel speed can then be controlled at the first vehicle 115.The option also exists in this case of terminating the turning maneuverif it is determined that the predetermined distance between the vehicles115, 120 cannot be maintained.

In both variants, following step 345, thus while the first vehicle 115carries out the turning maneuver, one or both trajectories 135, 140 canbe updated on the basis of observations. The observations can inparticular comprise updated trajectories 135, 140 of the vehicles 115,120. It can thus be taken into consideration when a driver of one of thevehicles 115, 120 changes the trajectory 135, 140 of their vehicle 115,120 with respect to the travel direction and/or travel speed. The method300 can be run through multiple times in the manner of a control loop.

REFERENCE NUMERALS

-   100 road-   105 first lane-   110 second lane-   115 first vehicle-   120 second vehicle-   125 further road-   130 control device-   135 first expected trajectory-   135.1 flatter first trajectory-   135.2 steeper first trajectory-   140 second expected trajectory-   145 first safety distance-   150 second safety distance-   155 further road user-   160 expected trajectory-   205 processing unit-   210 first device-   215 second device-   220 sensor-   225 communication unit-   230 position sensor-   235 map memory-   240 first interface-   245 steering unit-   250 second interface-   255 drive or braking unit-   300 method-   305 determining first trajectory-   310 determining second trajectory-   315 determining turning situation-   320 predetermined distance is undershot-   325 passing in front of second vehicle-   330 determining free space-   335 trajectory flatter-   340 increase travel speed-   345 control vehicle-   350 passing behind second vehicle-   355 determining free space-   360 trajectory steeper-   365 reduce travel speed-   370 update trajectory

1.-13. (canceled)
 14. A method for controlling a first vehicle withrespect to an oncoming second vehicle, the method comprising steps of:determining a turning situation of the first vehicle, in which anexpected first trajectory of the first vehicle crosses an expectedsecond trajectory of the second vehicle; controlling the first vehiclein such a way that a predetermined distance between the first and secondvehicles is maintained during the turning situation; wherein thecontrolling comprises influencing a travel direction of the firstvehicle.
 15. The method according to claim 14, wherein a steeringintervention on the first vehicle is controlled.
 16. The methodaccording to claim 15, wherein the steering intervention comprises apredetermined steering force, which is counteractable by a driver of thefirst vehicle.
 17. The method according to claim 14, wherein a travelspeed of the first vehicle is reduced before the crossing.
 18. Themethod according to claim 14, wherein the travel direction of the firstvehicle is dynamically controlled in dependence on a travel speed of thefirst vehicle.
 19. The method according to claim 14, wherein the traveldirection of the first vehicle is controlled in an increased manner in adirection of turning so as to increase a distance to an approachingsecond vehicle.
 20. The method according to claim 14, wherein the traveldirection of the first vehicle is controlled in a decreased manner in adirection of turning so as to increase a distance to the second vehiclemoving away.
 21. The method according to claim 14, wherein the firstvehicle is controlled in such a way that a predetermined distance to afurther road user is maintained.
 22. The method according to claim 14,wherein the first vehicle is returned to an original first trajectoryafter completely crossing the second trajectory.
 23. The methodaccording to claim 14, wherein an acceleration intention of a driver ofthe first vehicle is recognized and the influencing of the traveldirection of the first vehicle is switched off.
 24. A device forcontrolling a first vehicle with respect to an oncoming second vehicle,comprising: a first unit for determining an expected first trajectory ofthe first vehicle; a second unit for determining an expected secondtrajectory of the second vehicle; a processing unit, which is configuredto determine a turning situation, in which the determined expected firsttrajectory crosses the determined expected second trajectory; aninterface for connection to a unit for influencing a travel direction ofthe first vehicle; wherein the processing unit is configured toinfluence the travel direction of the first vehicle so that, that duringthe turning situation, a predetermined distance between the first andsecond vehicles is maintained.
 25. The device according to claim 24,further comprising: an interface for connection to a unit forinfluencing a travel speed of the first vehicle, wherein the processingunit is configured to reduce a travel speed of the first vehicle beforethe crossing.
 26. A vehicle comprising a device according to claim 24.